A reddish speck photographed near a dim and distant star last year is indeed a planet, about five times the mass of Jupiter, an international team of astronomers is reporting today.

They say the results bolster their claim, put forward last fall, that this image was the first of a planet orbiting a star outside the solar system.The planet, about 230 light-years from Earth in the constellation Hydra, orbits a kind of failed star known as a brown dwarf at a distance of at least five billion miles, twice as far as icy Neptune is from our own Sun. Spectroscopic measurements show water vapor in its atmosphere, suggesting that it is cold like a planet and not hot like a star, reports the New York Times.

The planet, about 230 light-years from Earth in the constellation Hydra, orbits a kind of failed star known as a brown dwarf at a distance of at least 5 billion miles, twice as far as icy Neptune is from our own sun. Spectroscopic measurements show water vapor in its atmosphere, suggesting that it is cold like a planet and not hot like a star.

"This discovery offers new perspectives for our understanding of chemical and physical properties of planetary mass objects as well as their mechanisms of formation," Gael Chauvin of the European Southern Observatory in Chile and his colleagues wrote in the paper, in the journal Astronomy and Astrophysics.

When Chauvin's group first announced the discovery of the object, known officially as 2M1207b, last year, they admitted that they could not prove that it was not just a background object unrelated to the brown dwarf.

Subsequent observations using the Very Large Telescope on Cerro Paranal in northern Chile and a system designed to take the twinkle out of starlight and thus get sharper images showed that the dwarf star and the suspected planet were moving together across the sky, cementing the notion that they are gravitationally bound, publishes the Moderate Voice.